Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 21 Feb 2014 15:06:16 -0800
From:      Craig Rodrigues <rodrigc@FreeBSD.org>
To:        attilio@freebsd.org
Cc:        FreeBSD Release Engineering Team <re@freebsd.org>, Xin Li <delphij@freebsd.org>, FreeBSD Security Team <secteam@freebsd.org>, Dmitry Sivachenko <trtrmitya@gmail.com>, Jung-uk Kim <jkim@freebsd.org>, "freebsd-java@freebsd.org" <freebsd-java@freebsd.org>
Subject:   Re: vm.pmap.pcid_enabled="0" seems to eliminate Java/Jenkins crashing problems in FBSD 10
Message-ID:  <CAG=rPVds7Z6EvSFuDsB3pJ401DvSkps0gq0Zy=MS7_Wp29JddQ@mail.gmail.com>
In-Reply-To: <CAJ-FndBKMg9NVm=qn2hmfEbFH-ZVPFr92gVHz3MkbgVXK=xpug@mail.gmail.com>
References:  <CAG=rPVeZGSs5_rRpRgdoSNK988TYY%2BBK76qeprWcR1JC64ekKQ@mail.gmail.com> <CAJ-FndBKMg9NVm=qn2hmfEbFH-ZVPFr92gVHz3MkbgVXK=xpug@mail.gmail.com>

next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, Feb 21, 2014 at 2:54 PM, Attilio Rao <attilio@freebsd.org> wrote:

> On Thu, Feb 20, 2014 at 5:45 AM, Craig Rodrigues <rodrigc@freebsd.org>
> wrote:
> > Hi,
> >
> > I am followed Jung-uk Kim's advice here:
> >
> >
> http://lists.freebsd.org/pipermail/freebsd-java/2014-February/010582.html
> >
> >
> > and configured the one of the FreeBSD stable/10 VM's (running at r261732)
> > that I have running
> > under BHyve with the
> > following in /boot/loader.conf:
> >
> > vm.pmap.pcid_enabled="0"
>
> IIRC PCID had to be already disabled by default as we saw it was
> slower in the real world or I'm missing something?
>
> Thanks,
> Attilio
>


I never observed an problems with speed problems being introduced by
vm.pmap.pcid_enabled="1".
All I can say is that I saw that Java VM crash when
vm.pmap.pcid_enabled="1", but setting
vm.pmap.pcid_enabled="0" stopped the crashes with the Java VM.

My focus was on stopping the Java crashes.

I still don't know the real cause of the problem...is it:

(1)  problem with new code that is executed when vm.pmap.pcid_enabled="1"
implementation?
(2)  latent bug in VM that is triggered by vm.pmap.pcid_enabled="1" but not
directly related to that?
(3)  bug in OpenJDK?

Hard to say for sure, but any help from a FreeBSD VM expert would be
greatly appreciated.

--
Craig



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAG=rPVds7Z6EvSFuDsB3pJ401DvSkps0gq0Zy=MS7_Wp29JddQ>